Phenobarbital Tablets
» Phenobarbital Tablets contain not less than 90.0 percent and not more than 110.0 percent of the labeled amount of C12H12N2O3.
Packaging and storage
Preserve in well-closed containers.
Identification
A:
Triturate a quantity of finely powdered Tablets, equivalent to about 60 mg of phenobarbital, with 50 mL of chloroform, and filter. Evaporate the clear filtrate to dryness, and dry at 105 for 2 hours: the residue so obtained responds to Identification test A under Phenobarbital.
B:
The retention time of the major peak in the chromatogram of the Assay preparation corresponds to that of the Standard preparation, both relative to the internal standard, as obtained in the Assay.
Dissolution 711
Medium:
water; 900 mL.
Apparatus 2:
50 rpm.
Time:
45 minutes.
Procedure
Determine the amount of C12H12N2O3 dissolved from UV absorbances at the wavelength of maximum absorbance at about 240 nm on filtered portions of the solution under test, suitably diluted with pH 9.6 alkaline borate buffer (see Buffer Solutions in the section Reagents, Indicators, and Solutions), in comparison with a Standard solution having a known concentration of USP Phenobarbital RS in the same Medium.
Tolerances
Not less than 75% (Q) of the labeled amount of C12H12N2O3 is dissolved in 45 minutes.
Uniformity of dosage units 905:
meet the requirements.
Assay
pH 4.5 Buffer solution, Mobile phase, Internal standard solution, Standard preparation, and Chromatographic system
Prepare as directed in the Assay under Phenobarbital.
Assay preparation
Weigh and finely powder not fewer than 20 Tablets. Weigh accurately a portion of the powder, equivalent to about 20 mg of phenobarbital, add 15.0 mL of Internal standard solution, mix, and sonicate for 15 minutes. Filter through a membrane filter having a 0.5-µm or finer porosity before use.
Procedure
Proceed as directed for Procedure in the Assay under Phenobarbital. Calculate the quantity, in mg, of C12H12N2O3 in the portion of Tablets taken by the formula:
(W)(RU / RS)
in which the terms are as defined therein.
Auxiliary Information
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Chromatographic Column
USP32NF27 Page 3271
Chromatographic columns text is not derived from, and not part of, USP 32 or NF 27.
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